SIEMENS QAE2121.015 Passive Immersion Temperature Sensor 1.5m

The SIEMENS QAE2121.015 is a high-performance passive immersion temperature sensor engineered for precise temperature monitoring in industrial and HVAC applications. Featuring an LG-Ni1000 sensing element, this sensor excels in environments with fluctuating temperatures, offering a reliable solution for critical temperature control. Its robust stainless steel construction and 150mm immersion length ensure durability and effective thermal transfer within pipes and tanks. Designed for straightforward integration, the QAE2121.015 connects via a G ½" threaded fitting and screw terminals, simplifying installation and maintenance. With a temperature measuring range of -30 to 130 °C and an accuracy of ±1.3 K, it delivers consistently accurate readings essential for optimal system performance and energy efficiency.

Product Specifications

| Feature              | Specification                                        |

| :------------------- | :--------------------------------------------------- |

| Manufacturer         | Siemens                                              |

| Product Number       | QAE2121.015                                          |

| Sensor Type          | Immersion Temperature Sensor                         |

| Sensing Element      | LG-Ni1000                                            |

| Immersion Length     | 150 mm                                               |

| Measuring Range      | -30 to 130 °C                                        |

| Accuracy             | ±1.3 K at -30 to 130 °C                              |

| Time Constant (no pocket) | 8 seconds                                            |

| Time Constant (with pocket)| 30 seconds                                           |

| Connecting Thread    | G ½"                                                 |

| Material (Immersion Pocket)| Stainless steel                                      |

| Protection Pocket    | Not included                                         |

| Electrical Connection| Screw terminals                                      |

| Dimensions (W x H x D)| 80 x 60 x 31 mm                                      |

| Nominal Pressure     | 16 bar (PN16) with AQE2102 compression fitting       |

| IP Rating            | IP42 (upgradeable to IP54 with M16 gland)            |

| Operating Temperature| -40 to +70 °C (housing)                              |

| Warranty             | 60 Months                                            |

Core Features & Market Positioning

The SIEMENS QAE2121.015 stands out in the competitive industrial sensor market due to its robust LG-Ni1000 sensing element, which provides excellent stability and accuracy across its operational temperature range. Unlike some competitors that may offer broader ranges with reduced precision, the QAE2121.015 focuses on delivering highly reliable temperature data within a critical HVAC and industrial process spectrum of -30 to 130 °C. Its stainless steel construction ensures longevity, even in demanding environments where corrosion or mechanical stress is a concern. The sensor's design, particularly its direct immersion capability and the option for secure fitting via a compression fitting, positions it as a practical and cost-effective solution for applications requiring straightforward yet accurate temperature measurement. The absence of a pre-included protection pocket offers flexibility, allowing users to select the most appropriate protection for their specific application, or to opt for direct immersion where suitable.

Key Application Scenarios

The SIEMENS QAE2121.015 immersion temperature sensor is ideally suited for a variety of critical applications within the heating, ventilation, and air conditioning (HVAC) sectors, as well as in general industrial process control. It is frequently specified for monitoring and regulating the flow temperature in heating circuits, ensuring optimal energy distribution and comfort. Its capability to limit return temperatures plays a vital role in protecting boiler systems and maintaining system efficiency. Furthermore, the sensor is employed for domestic hot water (DHW) temperature control, ensuring safe and consistent hot water supply. Beyond HVAC, its durable construction and precise readings make it suitable for monitoring temperatures in tanks and pipelines across various industrial processes where accurate temperature data is essential for product quality and operational safety.

Practical System Integration Guidance

Integrating the SIEMENS QAE2121.015 into existing systems is designed to be efficient. The sensor features a G ½" connecting thread, allowing for direct mounting into pipes or tanks using a compatible fitting or an optional protection pocket. For systems requiring a specific nominal pressure, using the AQE2102 compression fitting provides a reliable seal up to 16 bar (PN16). Electrical connections are made via screw terminals, which are accessible after removing the sensor's cover. The cable entry, typically a grommet, can be upgraded to a cable entry gland (M16) for enhanced protection, achieving an IP54 rating. For optimal performance, the immersion rod or protection pocket should face the direction of flow, and the sensor should be installed in a well-mixed area of the medium, typically downstream from pumps or mixing points, with a minimum immersion depth of 60 mm.

Operation and Risk Mitigation

The SIEMENS QAE2121.015 operates by converting the measured medium temperature into a change in resistance of its LG-Ni1000 sensing element. This passive signal is then transmitted to a compatible controller for processing. To mitigate risks, proper installation is paramount; ensuring the correct immersion depth and orientation prevents inaccurate readings and potential damage. While the sensor itself is robust, avoiding exposure to conditions exceeding its specified range (-30 to 130 °C) is crucial for longevity. The housing is rated IP42, but this can be increased to IP54 with the appropriate cable entry gland, safeguarding against dust and water ingress in more demanding environments. Regular inspection of the fitting and connections can prevent leaks or electrical faults.

Scalability & Long-Term Value

The SIEMENS QAE2121.015 offers significant long-term value through its compatibility with a wide array of Siemens HVAC and building automation systems. Its passive output signal is a standard in the industry, ensuring interoperability with controllers from various manufacturers. While the QAE2121.015 is a fixed-specification sensor, its integration into broader Building Management Systems (BMS) or Industrial Internet of Things (IIoT) platforms is achievable through compatible controllers and data acquisition gateways. This allows for centralized monitoring, data logging, and advanced analytics, contributing to predictive maintenance and optimized system performance over the product's lifecycle. The sensor's durable construction and Siemens' reputation for reliability further underscore its long-term investment value.

Frequently Asked Questions

Q1: What is the primary function of the SIEMENS QAE2121.015?

The SIEMENS QAE2121.015 is an immersion temperature sensor. It precisely measures the temperature of liquids in pipes and tanks. Its main role is to provide accurate data for control and monitoring systems.

This sensor utilizes an LG-Ni1000 sensing element. This technology ensures stable and reliable temperature readings. It is designed for continuous operation in industrial and HVAC applications.

Its measurements are crucial for maintaining optimal system performance and energy efficiency. It helps in precise temperature regulation within set parameters.

Q2: What is the temperature measuring range and accuracy of the QAE2121.015?

This Siemens sensor can accurately measure temperatures between -30 °C and 130 °C. This range is well-suited for many HVAC and industrial process applications.

The device offers a high level of precision, with an accuracy of ±1.3 K within its operating range. This ensures that system controls receive highly reliable temperature data.

Consistent accuracy is vital for energy efficiency and preventing equipment damage. The ±1.3 K tolerance ensures that temperature fluctuations are detected promptly.

Q3: How is the SIEMENS QAE2121.015 sensor installed and mounted?

Installation involves screwing the sensor into a pipe or tank fitting. A G ½" thread is standard for connecting the sensor.

It can be fitted directly or, for enhanced protection, with an optional protection pocket or a compression fitting like the AQE2102. The AQE2102 fitting supports up to PN16 pressure.

The immersion length is 150 mm, requiring a minimum immersion depth of 60 mm for accurate readings. Ensure the sensor is in a well-mixed flow area.

Q4: Does the QAE2121.015 include a protection pocket?

No, the SIEMENS QAE2121.015 is supplied without a protection pocket as standard. This offers flexibility for users to choose the most suitable protection.

Users can opt for a separate protection pocket or direct immersion. The choice depends on the specific application requirements and operating environment.

This design allows for easier replacement or selection of specialized pockets if needed. It also reduces initial cost if direct immersion is acceptable.

Q5: What are the key technical specifications of the QAE2121.015?

This sensor uses an LG-Ni1000 sensing element. It has an immersion length of 150 mm and a measuring range of -30 to 130 °C.

Its accuracy is rated at ±1.3 K at its operating temperature range. The time constant is 8 seconds without a pocket and 30 seconds with one.

The sensor connects via screw terminals and has a G ½" thread. The housing dimensions are 80 x 60 x 31 mm.

Q6: What industries and applications commonly use the Siemens QAE2121.015?

This sensor is predominantly used in HVAC systems. Applications include controlling flow and return water temperatures.

It is also utilized for domestic hot water (DHW) temperature control. In industrial settings, it monitors temperatures in tanks and pipelines.

Its precise and reliable performance makes it suitable for various process control scenarios. Anywhere accurate liquid temperature data is required, it is a strong candidate.

Q7: Can the QAE2121.015 be integrated into smart building or IIoT systems?

Yes, its passive signal can be integrated via compatible controllers. These controllers can bridge to BMS and IIoT platforms.

This allows for data logging and remote monitoring capabilities. It contributes to advanced analytics for system optimization.

The sensor's output is a standard resistance signal. This ensures broad compatibility with modern digital infrastructure.

Q8: What is the nominal pressure rating for the SIEMENS QAE2121.015?

The sensor's nominal pressure rating depends on its installation method. When used with the AQE2102 compression fitting, it can handle up to 16 bar (PN16).

If a different protection pocket or fitting is used, the nominal pressure will vary. It's essential to consult the specific accessory's specifications.

Direct immersion or standard fittings without specific pressure ratings should be carefully considered. Always ensure the chosen mounting method meets system pressure demands.

Q9: What is the time constant of the QAE2121.015 sensor?

The time constant refers to how quickly the sensor responds to temperature changes. Without a protection pocket, it responds rapidly at 8 seconds.

With a protection pocket installed, the response time increases to 30 seconds. This is due to the thermal resistance added by the pocket.

Choosing between direct immersion and a pocket depends on the need for speed versus protection. Faster response is critical for dynamic temperature control loops.

Q10: What is the warranty period for the SIEMENS QAE2121.015?

Siemens typically offers a robust warranty for its industrial products. The QAE2121.015 sensor comes with a warranty of 60 months.

This extended warranty period reflects the product's durability and Siemens' confidence in its reliability. It offers significant peace of mind for end-users.

Always refer to the specific purchase terms and conditions for full warranty details. This ensures proper claim procedures are understood.